DESCRIPTION: (Applicant's Abstract) The Crack and Health Service Use - A Natural History Approach study began admitting subjects in July 1996 and will terminate data collection activities in October 2000. Excellent progress has made to toward achieving the specific aims and productivity has been strong with 8 published articles and 10 presentations. This competing continuation application has two overall goals. The first is to continue to obtain data on the original sample to produce a natural history study of crack-cocaine use and health services utilization, drug abuse treatment in particular. The second is to assess the feasibility of extending the study to adolescent crack-cocaine users. Even though crack-cocaine has become part of the street pharmacopoeia, much is still unknown about its long-term use and consequences- and, especially why some of those who abuse crack and need treatment do not get it. In addition, there is evidence to suggest that increasing numbers of high school aged young people are using crack. This application proposes the continuing study of a sample of Dayton, Ohio, adult crack-cocaine users (n=419) and their utilization of health services, including drug abuse treatment. Qualitative methods will be used in the feasibility study which will focus on adolescent crack abusers (n=40) as well as key service providers who interact with them. The specific aims of this proposal are to: 1) Describe stability and change in substance abuse, health status, and health service utilization in our adult sample over an 8-year period; 2) Analyze the relationship between trajectories of drug use and health status over an 8-year period; 3) Identify the factors that predict the use of general health, mental health, and drug abuse treatment services over an 8 year period; 4) Conduct 45 qualitative follow-up interviews with the participants in the original sample to describe changes in drug abuse, drug abuse treatment experiences and other salient issues; and 5) Determine the feasibility of extending the natural history study to a sample of crack cocaine under 18 years of age.